Transmission



R. '6, LE TOURNEAU TRANSMISSION Filed July ll. 1942 INVENTOR 13G LEI Burneau,

HTTYS Patented Dec. 21, 1943 UNITED STATES PATENT OFFICE TRANSMISSION v Robert G. Le Tourneau, Peoria, 111., 'assignor to B. G. Le Tourneau, Inc., Stockton, Calii'., a corporation of California a Application July 11, 1942, Serial No. 450,559 (01. 74-360) 3 Claims.

This invention relates to transmission mechanisms for vehicles driven by internal combustion engines, and particularlytractors.

The principal object is to provide a transmission for the purpose so constructed that speed changes are effected without the movement of any gears into or out of mesh with each other, so that no gear clash or tooth stripping is possible.

A further object is to provide a transmission of this character soconstructed that it is impossible to lose control, as sometimes occurs under certain operating conditions, with conventional transmissions when attempting to shift from one gear to another. l

Another object is to arrange the transmission so that it may be readily connected to twin drive shafts, as when twin engines are used on the tractor, while at thesame time the transmission is also adapted, without material change, for use with a'single drive shaft and engine.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

The figure on the drawing is a sectional plan of my improved transmission, showing a set of intermediate speed gears as functioning Referring now more particularly to the characters of reference on the drawing, the structure comprises an enclosed housing I in which is journaled a pair of transverse and alined but spaced stub axles 2, on the outer end of which flanges 3 are mounted for attachment to suitable drive wheels. Eachaide within the hou'sing carries a bull gear 4 meshing with pinions 5 secured on separate stub spindles 6 journaled in the housing in alinement with each other and adjacent the rear end of said housing.

'Iransversely spaced parallel drive shafts 1, from separate twin engines, project into the housing from its front and at right angles to the axle 2. Within the housing these shafts carry bevel ears 8 meshing with bevel gears 9 fixed on a transverse countershaft i joumaled in the housing adjacent its forward end.

Separately turnable on the shaft Ill intermediate its ends are spur gears Ii and I 2 disposed somewhat close to each other. These gears are rigid with one member of clutches l3 and I4 respectively, disposed laterally out from the gears; the cooperating members of which clutches are splined on the shaft Hi. It will here be noted that while these and other clutches are here shown conventionally, in practice they are preferablyof a special-,type, such as shown in the copending application of 0. R. Peterson, et al.,- Serial No. 448,082, filed June 23, 1942.

The gears Ii and I2 mesh with other gears I! and I6 respectively, keyed on a second countershaft ll parallel to the shaft i0 and journaled in the housing rearwardly thereof; the pairs of gears being of different sizes to give different speed ratios.

Turnable on the shaft I1 is a pinion l8 meshing with a gear i9 keyed on a third countershait 20 journaled in the housing between and in line with the spindles 6. The pinion i8 is rigid with one member of a clutch 2i disposed laterally out from said pinion, the other member of the clutch being splinedon the shaft l1. Another pinion 22, larger than the pinion I8, is also turnable on the shaft i1 and meshes with a gear 23 smaller than the gear l9 and keyed on shaft 20.; The pinion 22 is, fixed with one member of a clutch- 24 disposed laterally out from said pinion, the cooperating member of the clutch being splined on the shaft ll. The pinions i8 and 22 are disposed on opposite sides of gears l5 and I6.

I able on the shaft 20. A pinion or gear 28 is disposed between and meshes with the pinion 26 and gear 21 sothat the latter turns in the same direction as said pinion. The gear 21 is fixed with one member of a clutch 29 disposed between gears 21 and IS, the other member of this clutch being keyed on the shaft 20. .It will thus be seen that a very compact gear and clutch arrangement is provided which occupies a minimum of space laterally. Also, since the axles are disposed in a plane intermediate the iront and rear shafts It and 20, the transmission as a whole is not excessively long. All the clutches are individually controlled, the clutches 25 being for the purpose of enabling one pinion 5 and its axle, or both, to be driven as may be desired, and provides an arrangement in this respect such as is commonly used for steering tractors of a certain type.

With the arrangement of parts and relative proportion of the gears as shown and above described, when it is desired to operate at the lowest or first speed, the clutches l4 and 2! only are engged, as well of course as either or both clutches The drive from the engin I, which is constantly imparted to the shaft i0, is then transmitted through gears l2 and I6, shaft I'I, pinion l8 and gear Hi, to the shaft 20 and then to the axle gears.

When the second speed operation is desired, the clutch l3, instead of the clutch I4, is engaged-clutch 2| remaining engaged also. The drive isqthen transmitted to gears II and I5, pinion I 8 and gear l9, and then to the axle gears, as before. This is the drive illustrated in the drawing. When third speed operation is desired the clutches I4 and 24 are engaged, the clutches l3 and 2| being then disengaged. The drive is then transmitted through the gears l2 and It to the shaft l1, and through pinion 22 and 23 to shaft 20.

For the fourth or high-speed drive the clutch I3, instead of the clutch It, is engaged, bringin the high speed ratio of gears H and 15 into play.

For a reverse drive the clutch 29 is engaged and either clutch I3 or l4 as well, the clutches 2i and 24 being of course disengaged. This gives an optional two-speed reverse drive, either through gears 12 and to the pinion 28, or through gears l l and i5 to said pinion and thence to the-gear 21 andshaft 20.

A power take-off shaft 30 i journaled in the housing and projects through the rear end of the same. 'This shaft is disposed below the countershafts and one of the engine shaft 1, being parallel to the latter. This take-off shaft is driven from said one shaft 1 by means of meshing gears 3| disposed between shaft I0 and the front end of the housing.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfill the objects of the invention as set forth herein.

While this specification sets forth in detail the present'and preferr d construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as set forth herein.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. A transmission mechanism comprising an engine driven'shaft, a final drive countershaft parallel to the first named shaft, another countershaft between and parallel to the other shafts, separate .pairs of constantly meshing gears of different speed ratios on the first and third named shafts disposed in relatively close relation, one gear of each pair being turnable on the engine ,driven shaft, separately operable clutches con necting said shaft and the tumable gears laterall out from the gears, other pairs of constantly meshing gears of different speed ratios on the final drive shaft and said other countershaft disposed laterally out from but adjacent the first named pairs of gears, one gear of each of said other pairs being tumable on the corresponding shaft, and separately operable clutches connecting said corresponding shaft and the last named tumable gears and disposed laterally out therefrom. i

2. A transmission mechanism comprising an engine driven shaft, a final drive countershaft parallel to the first named shaft, another countershaft between and parallel to the other shafts, sep rate pairs of constantly meshing gears of different speed ratios on the first and third named shafts disposed in relatively close relation, one gear of each pair being turnable on the engine driven shaft, separately operable clutches connecting said engine driven shaft and the turnable gears laterally out from the gears, other pairs of constantly meshing gears of different speed ratios on the final drive shaft and said other countershaft disposed laterally out from but adjacent the first named Pairs of gears, one gear of each of said other pairs being tumable on said other countershaft, separately .o rable clutches connecting said other countershaft and the last named tumable gears and disposed laterally out therefrom, a reverse gear train connecting the final drive shaft and said other countershaft and disposed between the second named pair of gears. said reverse train including a gear tumable on the final drive shaft, and a clutch connecting the final drive shaft and said last named tumable gear.

3. A transmission mechanism comprising a power driven shaft. a final drive countershaft parallel to the first named shaft, another countershaft parallel to and between the other shafts, separate pairs of constantly meshing gears of different speed ratios on the first and third named shafts, one gear of each pair being tumable on the driven shaft, separately operable clutches connecting said driven shaft and the tumable gears, other pairs of constantly meshing gears of different speed ratios on the final drive shaft and said other countershaft, one gear of each of said other pairs being tumable on said other countershaft, separately operable clutches connecting said other countershaft and the last named tumable gears, a reverse gear train connecting the final drive shaft and said other countershaft, said reverse train including a gear tumable on the final drive shaft, and a clutch connecting the final drive shaft and said last named turnable gear.

, ROBERT G. LE TOURNEAU. 

